Field of the Invention
The present invention relates to a method of preventing sensitive brake of a vehicle, and more particularly, to a method of preventing a sensitive brake of a vehicle, which adjusts oil pressure of a brake caliper in next brake based on an index calculated by measuring a braking speed of a vehicle, and prevents a sensitive brake.
The present invention also relates to an apparatus for preventing a sensitive brake of a vehicle for implementing the method of preventing a sensitive brake.
Description of Related Art
In general, a disk brake of a vehicle includes a caliper, which includes a brake disk rotating while being integrated with a vehicle wheel, a pad generating frictional force while being in close contact with a disk, a wheel cylinder to which oil pressure is applied, a piston reciprocating inside the cylinder and pushing the pad, and a cylinder, as a main element.
When a driver steps on a brake pedal in order to decelerate or stop a vehicle while travelling, the disk brake of the vehicle pushes the piston within a master cylinder and forcibly transfers a brake liquid to a wheel cylinder by the force of the stepped on corresponding brake pedal to generate oil pressure, and the pressurized oil of the brake liquid flows into the corresponding wheel cylinder through a brake pipe to break the piston in left and right sides, so that a brake shoe is pushed against a brake drum to generate braking force, and when the driver takes his/her foot off the brake pedal, the oil pressure within the corresponding master cylinder deteriorates, so that the corresponding brake shoe returns to an original position by restoration force of a return spring, and the brake liquid within the corresponding wheel cylinder returns to the corresponding master cylinder, so that the braking force is released.
The brake apparatus exhibits a sensitive brake effect, in which excessive braking force is applied, when the vehicle travels after being parked during the night time, and the sensitive brake effect is generated because humidity of a friction material is increased during the night time according to a characteristic of the friction material and a frictional coefficient is abnormally increased to implement excessive braking force. However, when the driver repeatedly brakes several times, a temperature of a brake system is increased and the humidity of the friction material is returned to a normal state, so that the sensitive brake effect disappears.
The sensitive brake effect may degrade a ride quality of a passenger and generate noises, and has a concern in causing a collision accident by a rear vehicle due to a sudden brake, so that it is necessary to prevent the generation of the sensitive brake effect.
The prior art discloses technology, in which a function of turning off an ignition switch while a travel driving source of a vehicle is stopped and there is no brake operation of a driver of the parked vehicle, or operating a service brake while each of the conditions that a gear shift is a P range and a stop lamp switch is turned off is added to a brake apparatus for a vehicle, so that the brake apparatus is left so that the amount of moisture absorbed by a friction material is decreased, and then a sensitive brake of the brake generated while braking the vehicle (particularly, a brake at an initial start) is suppressed.
However, in reality, it is difficult to accurately measure the amount of moisture absorbed by the friction material.
Prior art discloses a method and an apparatus for re-adjusting friction, in which a service brake shaped like a drum or a disk, a secondary brake, a control device for distributing braking force demanded between the service brake and the secondary brake, and an apparatus for re-adjusting a friction material forming a part of the service brake are provided to a vehicle.
However, the control device for distributing braking force needs to be further provided in order to re-adjust the friction force of the friction material in the patent technology, so that there is a problem in that manufacturing cost is increased, and the control device needs to be additionally managed and maintained in an optimum state in order to accurately distribute braking force.
Further prior art discloses an apparatus for removing moisture of a brake system including a heating substance operated for a predetermined time to generate heat to a friction material of a brake system, which is compressed against a brake drum or a disk while braking to generate braking force, in order to remove moisture or water by heating the friction material by heat generated from the heating substance when a vehicle is traveled after being parked for a long time in winter season or being washed.
However, there is a problem in that the additional heating substance is included in order to remove moisture or water of the friction material to increase costs, and it is difficult to install the heating substance in the brake apparatus due to a limitation in a small space.
The information disclosed in this Background of the Invention section is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art.